Rotary pump apparatus



Dec. 14, 1943. I c FULCHER 2,336,475

' IROTARY PUMP APPARATUS Filed May 9, 1941 5 Sheets-Sheet 1 INVEWITOR Dec. 14, 1943. F FULCHEg 2,336,475

ROTARY PUMP APPARATUS Filed May 9 i941 58heets-Sh'eet. 2

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ATTORNEY F. c. FULCHER ROTA RY PUMP APPARATUS 5 Sheets-Shef 3 Filed May 9, 1941 I/Vl/E/VTOR mar-{m Dec. 14, 1943. c, u c I i I 2,336,475

ROTARY PUMP APPARATUS Filed May 9, 1941 5 Sheets-Shee t 4 4 rrnD/VEY Dec. 14, 1943. q FULCHER 2,336,475

ROTARY PUMP APPARATUS Filed May 9, 1941 5 Sheets-Sheet 5 w m W I I JNvENTok A er d'eaqzkm ATTORNEY Patented Dec. 14, 1943 ROTARY PUIMP'APPARATUS Frank Christian Fulcher, Kentsbank, Grangeover-Sands, England Application May 9, 1941, Serial No. 392,699 In Great Britain May 20, 1940 13 Claims. (01. 230-157) The present invention relates to rotary vane pumps of the kind in which the vanes are mounted to rotate within a working chamber and pass through slots in the wall of a barrel-like rotor so as to project inside and outside the barrel which also rotates within the chamber about an axis eccentric to that about which the vanes rotate, so that a relative sliding movement between the vanes and the rotor is produced when the rotor and vanes turn and the ends of the vanes are carried round the peripheral wall of the working chamber. The invention is particularly but not exclusively applicable to high speed vacuum pumps for the operation of suc-" tion-driven instruments and gauges on aircraft or to pressure pumps for use as superchargers or blowers onaircraft for charging the cabin or other occupied interior of the aircraft with air at a greater pressure than that of the surrounding atmosphere as for example is necessary at .high altitudes, or for use in the operation of deicing equipment. In some cases the pump serves the double duty of vacuum pump for operating instruments and as pressure pump for operating the de-icing apparatus; Vacuum pumps for the aforesaid purpose may run at speeds varying from 800 to 4,500 R. P. M., with a normal or cruising speed of the order of about 2,000 R. P. M., if the pump is driven direct from the engine. There are various classes of-pump of the foregoing type to which the present invention can be applied. In some forms the vanes pass from one side of the working chamber to the other intersecting within the barrel. In other forms the inner ends of the vanes slide around a tube or cylinder arranged centrally of the working chamber or approximately so whilst the outer ends centrifuge against the inner wall of the working chamber. In some cases the vanes are constrained against centrifuging but do not pass completely through the barrel, e. g., the inner ends of the vanes may be provided with spaced intercalating eyes mounted upon a spindle centrally of the working chamber. In this latter class, in some cases, only the space in the working chamber around the barrel is utilized but I prefer to utilize not only that space but the space within the barrel and in fact a very convenient application of the present invention is to the pumps described and claimed in my co-pending lateral, e. g., tangential, ports, one port may selectively serve as an inlet port and one as an outlet port, depending upon the direction of rotation of the rotor and vanes; if the ports are tangential and lead from the working chamber in the same direction and the rotor is displaced in the working chamber in such direction, a short flow through the apparatus is available, the fiowthrough being longer when the barrel is displaced in the working chamber in the opposite direction. In either case however the direction of rotation of the rotor and consequently of the flow of the gaseous medium through the apparatus may be chosen at will.

An object of the present invention is to adapt the pump, withoutunduly increasing its bulk and weight, so that the rotor may be rotated in either direction without reversing the flow of the gaseous medium through one part of the apparatus. For example in the case of a cabin supercharger, it may be desired to discharge air unpolluted with oil used for lubricating the pump through an oil separator and/or it may be required to pass the air discharged from the working chamber over a heating or other air treating apparatus. It may be desirable in other cases to allow cold incoming air to pass over bearings or other parts liable to run hot. In any of these cases a uni-directional flow through the appropriate part of the apparatus is required irrespective of the direction of rotation of the rotor and vanes. On the other, hand, a pump which can only work efiectively when run in' one direction is very disadvantageous when the pump is a unit which may have to be coupled to a shaft or other appropriate part the direction of rotation of which is not known when the pump is made.

Another object of the present invention is to provide a pump apparatus which is ported topermit of the desired uni-directional flow through a passage or chamber in the apparatus where such a flow is required, but will also be capable of running in eitherdirec'tion of rotation,

' and according to this inventioruthe working chamber of the pump is provided with twou'pairs of ports, of which one of one pair-and onesoflthe other are arranged to be'closed at any onetime/ to permit the flow through the working-chamber in one direction, whilst-these two" ports are opened and the other two closed':'topermit the flow. to take place'inthe-r'everse dire'ction -when the direction of -rotation-of the'roto'r'fand times direction irrespective of the direction of rota-' tion of the external driving motor or the like to which the pump is coupled and of the direction of flow through the working chamber.

Another object of the invention is to utilize as part of the passage through the apparatus for the gaseous medium a passage or chamber which exists between spaced anti-friction bearings which are inserted through one end of an extension containing a shaft of the rotor in order to obtain the desired unidirectional flow without unduly increasing the size and bulk of the apparatus.

A further object of the invention is to provide a standardized pump casing and detachable components attachable thereto selectively after the direction in which the pump is to rotate is known.

A further object of the invention is to reduce the length of path for the gaseous medium through the apparatus as far as possible con-' sistent with permitting the desired unidirectional fiow irrespective of the direction of reically adapted to operate in the given one of the two directions of rotation.

To provide these alternative ports in a convenient manner the pump is preferably provided with alternative lateral ports and with alternative end ports. The lateral ports are preferably arranged one on one side and one on the other side of the longitudinal axis of the pump and may lead approximately tangentially in abreast relation into the working chamber. The end ports direct the air discharged from the working chamber towards the end of the pump either in a direct path or in an angled or inclined path and preferably lead to an annular passage having a single outlet which may extend laterally, e. g., radially. Alternatively the lateral ports may be the delivery ports and the end ports the suction ports, e. g., where it is desired to use the incoming cold air to cool the rotor shaft.

A notably compact arrangement is produced.

action the air flow is from the working chamber 'unidirectionally through the extension and then a single port-which will be a discharge port, or in ther forms of apparatus an inlet port which may extend axially but is conveniently arranged laterally, e. g., radially, and is in communication with the annular chamber with which'the two ports communicate. The alternative end ports may be so arranged as to direct the air flow first axially and then towards the rotor shaft to the annular chamber or vice versa where the single port is an inlet port.

Where the rotor barrel is supported cantilever fashion, as described in my co-pending applications aforesaid, byspaoed bearings, preferably 2,886,475 is reversed, and the ports of one of the pairs *anti-friction, e. g., ball, bearings co-operating with the rotor shaft in the casing extension, an annular chamber is already present in the extension between the spaced bearings so as to allow the two bearings to be inserted into the casing extension from one end of the latter. I can therefore introduce the alternative porting system into such a pump with very little extra weight of metal or increase in bulk by providing the working chamber with two lateral ports as is ordinarily required, but making these ports both inlet ports or both outlet ports, and by providing the alternative end ports as short passages in the casing around the inner bearing, these ports placing in communication with the working chamber the said annular passage which is ordinarily sealed off therefrom. A single delivery or suction port is providedfor this passage.

When non-return valves are employed, they may be of any convenient compact form mounted in the end alternative delivery ports so that automatically the pressure produced within the working chamber opens the one port whilst the other port remains closed during the working of the pump.

I employ a form of non-return valve which will be readily responsive to the pressures within the pump chamber. In the form of apparatus hereinafter described, the valve opens against the resistance of a comparatively light spring and provision is made for so securing the valve in position in the port as not to vary, as a result of fitting the valve to the pump, the predetermined resistance which the spring offers to the opening of the valve. Another form of valve which is suitable is one composed of one or more annularly slotted spring diaphragms, e. g., of the Hoebiger type.

The provision of the non-retum valves is advantageous because it obviates the necessity for the user to determine which of the discharge ports is to be closed. The suction port which is not wanted has to be plugged and it is a simple matter to ascertain by means of a manometer that the proper suction port has been left open after connecting up the pump and having plugged one port.

In order that the invention may be more readily understood, reference is hereinafter made to the accompanying drawings depicting two forms of apparatus incorporating the present porting system.

Fig. 1 is a longtiudinal sectional elevation of the first form of apparatus, Fig. 2 is a longitudinal sectional elevation at right angles to Fig. 1, and Fig. 3 is a. half-sectional end view of the apparatus, Fig. 1 being taken on the line |l of Fig. 3 and'Fig. 2 on the line 2-2 of that figure. Fig. 4 is a fragmentary view of a modified device for closing one delivery port and this device is interchangeable with the plug, Fig. 5, which is used in the other delivery port to keep this open while shutting off the port from the exterior of the pump. Fig. 6 is an external view from the same aspect as Fig. 1 and Fig. 'I an external view from the same aspect as Fig. 2. 1 Fig. 8 is a, longitudinal elevation, Fig. 9 an end view, Fig. 10 a plan view and Figs. 11 and 12 sectional plan views on the line A-B, Fig. 8

showing diagrammatically how the pump may be adapted for selectively by-passing the pas sage around the shaft. Fig. 13 is a view similar to Fig. 9 of a modified construction which may be employed to achieve the same results when the the working cylinder.

direction of rotation of the pump is previously known. Fig. 14, is a part longitudinal sectional elevation from the same aspect as Fig. 2, showing how the valves which control communication between the working chamber and the said passage may be mounted in a separate fitting which is ribbed to promote cooling, Fig. 15 being a half-plan of such fitting and Fig. 16 an end view thereof. Fig. 17, is a fragmentary sectional elevation from the same aspect as Fig. 3 of a modified construction of the ports so that the port which is the inlet in Fig. 3 is applicable as the outlet by reversing the direction of flow through the passage around the shaft.

The apparatus chosen for illustration of the present invention is that described and claimed in our co-pending-application Serial No. 393,268, in which a uni-directional flow is required, irrespective f the direction of rotation of the rotor and vanes, of the air discharged through an oilseparator A into the occupied interior of the aircraft or to the de-icing equipment thereof. In this form of apparatus the flow is always from the working chamber to a single discharge port more remote from such chamber.

The pump apparatu comprises a casing l providing a working chamber 2 of cylindrical form in which is eccentrically mounted the barrel 3 of a rotor, the shaft 4 of which projects into an extension 5 of the casing. The barrel wall is slotted to house oscillatable bearing pins 6 which are themselves slotted or-similarly formed slidably to receive the vanes l which have intercalated eyes 8 which are rotatably supported by a spindle 9 which is fixed tothe end wall H) of the casing and projects cantilever fashion into Both the inside of the rotorbarrel and the spaces between the barrel and the cylindrical wall of the working cylinder are usefully employed in the displacement of the air or other gaseous medium, the end wall l0 being divided into two components, the inner wall component ll being appropriately ported at I2, I3, l4 and to co-operate with the conduplicated compartments of the chamber l5 between the inner component I! and the outer component l7 of the end wall. 'Ihese compartments are formed by 'a dividing web lla on the outer wall component. I do not propose to give a fulle general description of the pump, since it is fully described in my aforesaid applications, but I draw particular attention to the fact that the barrel of the rotor is supported cantilever fashion in the working chamber by the support of the rotor shaft by means of the spaced ball bearings l8 and I9. In my previous applications the annular passage provided between these two bearings is substantially closed 01f from the working chamber.

In accordance with the present invention; two inlet ports 2| and 22 lead into the working chamber substantially tangentially thereto and preferably from the same side of the chamber as that on which the barrel is displaced and either one of these ports is adapted selectively to be closed port 21. The outlet ports 24 and 25 lie in the casing outside of the inner bearing l8. The single delivery port 21 is conveniently near the re.- mote bearing l9.

In Figs. 1 to 3 the outlet ports 24 and 25-are each controlled by a non-return valve 28 which opens by the pressure of the gaseous medium within the pump chamber one port being always arranged on the suction side and th other on the delivery or pressure side whichever direction of rotation is selected so that only one valve is open at a time. Each such valve is opened against the pressure of a light spring 29 which renders the valve responsive to comparatively low pressures.

The valve-securing plug 30 positions the valve through the medium of an intermediate ported slide 3| which is forced against a shoulder 32 by a stifi spring 26 while screwing-in plug 30. Consequently the compression of the light valve spring 29 is unaffected by the extent to which between the working chamber and the passage terchangeable and arepositioned according to the direction of rotation of the rotor.

It will be observed that the valve means in Figs. 1 to 3 are, like the plugs just described, removable from the exterior of the apparatus, and like the plugs they serve to close the ports to the exterior of the apparatus.

The extension of the casing may be integral with the cylindrical part of the casing which forms the outer wall of'the working chamber and may be bored out centrally to receive the ball. bearings and the oil separator (when this is provided). Tl e delivery ports 24 and 25 may be formed by bores parallel to the axis of the working chamber in offset chambers 31 of said by a plug 23 which is shown for the purpose of illustration as closing the port 22, as it does when the rotor turns in the direction shown by the arrow A. This plug is removable and insertable.

into the other port when the rotor is required to run in the reverse direction.

From the working chamber two outlet ports casing and slot-like bores or ports 26 milled from the inside at right angles thereto lead to the passage 20. It may, however, be more convenient in some cases to form the extension in separate parts, e. g., parts secured together by peripheral engagement. The said bores in the offset chambers may be formed from the rear and may have lateral ports or openings 2611 by which the bores in the ofiset chambers communicate with the working chamber. Thus one offset chamber has an inlet port 2| and a delivery port 24 and the other oifset chamber corresponding ports 22, 25. The lateral or radial common outlet 2'I'may be connected with the large shoul- 'dered central passage by a short slot-like passage 39 milled from the inside.

The passage 20 Within the casing extension may be sealed at the remote end against exterior communication through the remote bearing sealing rings or annuli between the two races of,

the outer ball bearing.

.The apparatus illustrated may be used for I supplying compressed air to the interior'of the air-craft or to the de-icing equipment. The uni-directional flow of the air through an oil separator is desirable in the latter casein order to avoid damaging access of lubricating oil from the pump to the rubber of such equipment. A stationary form of separator is disclosed, but a rotary or centrifugal form as in my aforesaid co-pending application Serial No. 392,700 may equally serve.

cial value where a standardized product is required. For example it may be desired to use the pump, or to use it sometimes, without relying upon a unidirectional dischargeor entry of the displaced medium and in this case both liability of leakage past a non-return valve which 2 .is never. required to be open to the passage 20.

Referring to Figs. 8 to 12 it is allowable to bridge each of the inlet ports 2| and 22 and the single discharge port 21 by a short internal passage or (as shown) external pipe 42, 42a, 42b con- 3 taining a valve 43 andan intermediate exit 44 so that whichever port (port 2| in the example shown) is in use as the inlet port, by appropriately positioning the valve, the other of the inlet ports, port 22 in the illustration can be made an outlet so that the air can be discharged directly through such exit 44 instead of passing through the passage 20, see Fig. 11, or alternatively, the valve can beoperated to compel the air to reach such exit only after passing through such passage (see Fig. 12). This is especially convenient when the apparatus is to be used for the dual purpose of a vacuum pump for operating instruments and as a pressure pump for operating de-icing equipment, since when the 4:;

pump is operating the instruments only, the valves can be moved to permit the direct discharge (By-passing the passage 20) through such exit, whereas when the pump is to operate deicing equipment the valves are operated to compel the air to pass through the passage 20 and the separator on its way to such exit. The-inlet not used is plugged to the exterior, see plug 45, so that 'the discharge, is past the valve and through the exit 44.

When the direction of rotation is known, one 4 of suchpipe components 42a, 42b need be fitted (see Fig. 13, which has pipe component 42b only). If desired, in order to simplify the casting of the casing of the apparatus, and in order no .to cool the air from the working chamber before passingaround the rotor shaft, externally ribbed tubes 46 see Figs. 14 to 16 may be attached to the pump casing by bolts 41 to formthe ports between the working cylinder and the passage 20 and the ribs or fins 48 may be arranged in the slip-stream, or one of such tubes may be fitted if the direction of rotation is known. The casing maybe appropriately formed at 49 to enable such a tube or tubes to be readopen by pressure of the fluid created within the ily coupled to it by way of 'th e flanges 50, 5|.

Each fitting forms that parftof the oifset chamher which comprises the delivery port, see Fig.

14, where the chamber ,thatinc ludes port 24 is form to provide the main bore, of the delivery port 24, which runs parallel to the axis of the working chamber, the air which passes through said bore bein cooled by the action of the cold air passing externally over the cooling ribs. The interior air is thus cooled prior to entry to the separator. The valve 28 and associated parts are included in this fitting which is generally similar to the corresponding integral part The construction of pump described is of espe- 10 of the casing of the form shown in Fig. 2, the lateral openings corresponding to those 26a, 26b in the latter form, being provided by openings 260, 26d in the fitting registering with openings 26e, 26f in the casing.

Where the port 21 is used as an inlet port, the ports 24 and 25 as inlets to the working chamber and the ports 2| and 22 as outlets therefrom, the non-return valves may be provided in the latter ports (see Fig. 17) instead of in the 0 end ports 24 and 25 which may be of the form shown in Figs. 4 and 5.

What I claim is: 1. A high speed rotary pump apparatus for displacing gaseous medium which comprises a 5 casing having a'peripheral walland end walls forming a working chamber and having an axial extension provided with a hollow interior opening through one of said end walls into said chamber, a rotor having a barrel portion eccen- 0 trically arranged in said chamber, said barrel having one end open and in working relation to one end wall of the-casing and the other end closed and in working relation to the other end wall of the casing and a shaft projecting from said closed end wall of the barrel, said rotor dividing said working chamber from vthe interior of said extension, said shaft extending from said barrel into said hollow extension, spaced antifriction bearings supporting said shaft in said extension, a plurality of vanes slidable through the peripheral wall of the barrel and rotatable therewith and. adapted to produce chambers of varying volume within said working chamber, said casing having two chambers offset from and communicating with the working chamber, a passage in said extension interior around said shaft and between said spaced bearings, each of said offset chambers having an inlet port and a delivery port, one of said ports for each chamber placing its said ofiset chamber in communication with said passage and the other of said ports for each chamber placing its said offset chamber in communication with the pump exterior, said passage having a port at its end remote from said offset chambers, separate closure means for closing the inlet port of one of said ofiset chambers, and separate closure means for closing the delivery port of the other of said offset chambers so that depending upon the direction of rotation of said barrel and vanes only one of the inlet ports and only one of the delivery ports remains open and th displaced medium moves in the same direction throughsaid passage ir-'- respective of the direction of rotation, the outer end of said shaft being constructed for coupling to an external driving means.

2. A high speed rotary pump apparatus according to claim 1, in which separate closure means are provided in both of said delivery ports, said separate closure means being adapted to working chamber, and one of said means-in one jected to such pressure during the rotation of shown. This said partis generally of tubular the barrel and vanes and the other being grextensionprovided with a hollow interior opening through one of said end walls into said chamber, a rotor having a barrel portion eccentrically arranged in said chamber and comprising at one end at least a shaft, said rotor dividing said working chamber from the interior of said extension, said shaft extending from said barrel into said hollow extension, spaced anti-friction bearings supporting said shaft in said extension, a plurality of vanes slidable through the peripheral wall of the barrel and rotatable therewith and adapted to produc chambers of varying volume within said working chamber, said peripheral wall of the casing having two local enlargements providing chamber offset from and communicating with the working chamber, a passage in said extension interior around said shaft said offset chambers, separate closure means for closing the inlet port of one of said ofiset chambers with the running of the pump in a chosen direction of rotation and separate means for closing the delivery port of the other of said offset chambers so that depending upon the chosen direction of rotation of said barrel and vanes only one of said inlet ports and only one of said delivery ports remain open and the displaced medium moves in the same direction through said passage irrespective of the direction of rotation.

4. A high speed rotary pump apparatus for displacing gaseous medium which comprises a casing having a peripheral wall and end walls forming a working chamber and having an axial extension provided with a hollow interior opening through one of said end walls into said chamber, a rotor having a barrel portion eccentrically arranged in said chamber, said barrel having one end open and in working relation to one end wall of the 'casing and the other end closed and in working relation to the other end wall of the casing, and a shaft projecting from said closed end wall of the barrel, said rotor dividing said working chamber from the interior of said extension, said shaft extending from said barrel into said hollow extension, spaced anti-friction bearings supporting said shaft in said extension, a plurality of vanes slidable through the peripheral wall of th barrel and rotatable therewith and adapted to produce chambers of varying volume within said working chamber, said casing of said ports for each cha'mberplacing its ofisetchamber in communicationl with said. passage,

said passage having a port-at its end remote from said offset chambers, separate closure means for plugging one or the other of said inlet ports in accordance with the direction of shaft rotation and automatic valves in'each of said delivery ports adapted to open under the pressure and to close under the suction prevailing in the working chamber so that in either direction of rotation of said barrel and vanes, the displaced medium moves in the same direction through said passage, the outer end of said shaft being constructed for coupling to an external driving means.

5. A rotary pump apparatus according to claim 3, in which one port of one offset chamber and the corresponding port of the other offset cham working chamber on which the barrel is situat-' ed and the other ports of said offset chambers being each situated nearer to their companion tangentially directed ports than to each other.

6. A rotary pump apparatus according to claim 1', comprising means for sealing the outer end of the passage, a mounting plate on the casing beyond the end of the passage for attaching the apparatus to a source of drive, said shaft extending through said plate, and said passage having its port remote from the working chamber opening through the peripheral wall of the passage.

'7. A high speed rotary pump apparatus for displacing gaseous medium which comprises a casing having a peripheral wall and end walls forming a working chamber and having an axial extension provided with a hollow interior opening through one of said end walls into said chamber, a rotor having a barrel portion eccentrically arranged in said chamber,said barrel having one end open and in working relation to one end wall of the casing and the other end closed and in workin relation to the other end wall of the casing, and a shaft projecting from said closed end wall of the barrel, said rotor dividing said working chamber from the interior of said extension, said shaft extending from said barrel into said hollow extension, spaced anti-friction bearings supporting said shaft in said extension, a plurality of vanes slidable through a wall of the barrel and rotatable therewith and adapted to produce chambers of varying Volume within said working chamber, said casing having two chambers offset from and communicating with the working chamber, a passage in said extension around said shaft and between said spaced bearings, each of said offset chambers having an inlet port and a delivery port, one of said ports for each chamber placing its said ofiset chamber in communication with said passage and the other of said ports for each chamber placing its ofiset chamber in communication with the pump exterior, said passage having a port at its end remote from said offset chambers, separate 'closure means plugging one of the ports which place said offset chambers in communication with the pump exterior and means for alternatively closing either one'of the ports which place said offset chambers in communication with said passage, said last mentioned means comprising in-, terchangeable plugs fitted from externally of the pump into said ports, one of said plugs being fitted.in said ofisetchamber whose port which communicates with the pump exterior is open for such communication, said one plug closing theport which communicates with the working chamber and the annular passage, and another of said plugs being fitted to the other of said offset chambers whos port which communicates between the working chamber and the pump l exterior is closed, said last mentioned plug being formed to allow communication between the working chamber and the passage, so that depending upon the chosen direction of rotation of said barrel and vanes only one of said inlet ports and'only one of said delivery ports remain open and the displaced medium moves in the same di- 9. A rotary pump apparatus according to claim 4, in which one of said ports for each offset chamber communicates with the working chamber and the annular passage and opens to the exterior of the apparatus, said automatic valves being removably arranged in said port-for each said chamber so as to close off the port to the exterior and to open or close communication between the working chamber and the passage depending upon whether the valve is subjected to pressure or not.

10. A high speed rotary pump apparatus for displacing gaseous medium which comprises a casing having a peripheral wall and end walls forming a working cylinder and having an axial extension provided with a hollow interior having a cylindrical opening into one end wall of the said cylinder the other end wall of the cylinder having an annular groove coaxial, with said openspaced bearings, each of said offset chambers having an inlet port and a delivery port, one

of said ports for each chamber placing its said offset chamber in communication with said passage and the other of said ports for each chamber placing its offset chamber in communication with the pump exterior, said passage having a port at its end remote from the offset chambers, separate closure means closing the inlet port of one of said offset chambers and separat means for closing the delivery port of the other of said offset chambers for the running of the bar rel and vanes in a chosen direction so that depending upon the direction of rotation of said barrel and vanes only one of said inlet ports and only one of said delivery ports remain open during such rotation and th displaced medium moves in the same direction through said passage irrespective of the direction of rotation, the

outer nd of said shaft being constructed forextensiomprovided with a hollow interior opening, said groove and said opening being eccentric "shaft extending from the closed end wall of said barrel through said hollow extension interior, spaced antifriction bearings supporting said shaft in said extension, a spindle rigidly fixed in said grooved end wall so as to project cantilever fashion into the working cylinder centrally thereof, a plurality of vanes provided with hearing eyes which are rotatably supported by said spindle and which constrain the vanes from centrifuging, slotted cylindrical bearing members oscillatable in the peripheral wallof said barrel, said vanes passing through the slots in said mem bers and said members and said vanes being relatively slidable, said vanes being arranged to generate with the cylinder walls and with the inner and outer walls of the rotor barrel pump I working chambers of varying capacity both inside and outside of said rotor barrel and said casing being ported to co-operate with said inside and outside working chambers, said cas ing providing two chambers offset from and communicating with the working chamber, an annular passage around said shaft between said ing through one of said end walls into said chamber, a rotor having a barrel portion eccentrically arranged in said chamber, said barrel having one end in working relation to one end wall of the casing and the other end in working relation to the other end wall of the casing and a shaft projecting from at least one end wall of the barrel, said rotor dividing said working chamber from the interior of said extension, said shaft extending from said barrel into said hollow extension and being supported in said extension, a plurality of vanes slidable through the peripheral walls of the barrel and rotatable therewith and adapted to produce chambers of varying volume within said working chamber, said casing having two chambers offset from and communicating with the working chamber, a passage in said extension interior around said shaft, each of said offset chambers having an inlet port and a delivery port one'of said ports for each chamber placing its said offset chamber in communication with said passage and the other of said ports for each chamber placing its said oilset chamber in communication with the pump exterior, said passage having a port at its end remote from said offset chambers, separate closure means for closing the inlet port of one of said offset chambers and means for closing the delivery port of the other of said offset cham bers with the rotation of the barrel and vanes in a chosen direction so that depending upon the direction of rotation of said barrel and vanes only one of said inlet ports and only one of said delivery ports remains open and the displaced medium moves in the same direction through said passage irrespective of the direction of Totation, the outer end of said shaft being constructed for coupling to an external driving means.

129A high speed rotary pump apparatus for displacing gaseous medium which comprises a 'casing having a peripheral wall and-end walls forming a working chamber and having an axial extension provided with a hollow interior opening through one of said end walls into said chamher, a rotor having a barrel portion eccentricalof the casing and theother end in working relation to the other end wall of the-casing and a shaft projecting from at least one end wall of the barrel, said rotor dividing said working chamher from the interior of said extension, said shaft extending from said barrel "into said hollow extension and being supported in said extension, a plurality of vanes slidable through the peripheral wall of the barrel and rotatable therewith and adapted to produce chambers of varying volume within said working chamber, said casing having two chambers offset from and communicating with the Working chamber, a passage in said extension interior around said shaft, said passage having a port at its end remote from said .ofiset chamber, each of said offset chambers having an inlet and a delivery port, one of said ports for each chamber placing its said offset chamber in communication with said passage, a conduit placing the other of said ports for each chamber in communication with said port in said passage, an intermediate opening from said conduit and valve means in said conduit operative to couple said intermediate opening directly with the working chamber and thereby by-pass said passage or to couple said opening for communication with said passage,

separate closure means for closing the inlet port of one of said ofiset chambers and means for closing the delivery port of the other of said ofiset chambers for a chosen direction of rotation of the barrel and vanes so that depending upon the chosen direction er rotation of said barrel and vanes only one of said inlet ports and only one of said delivery ports remains open and the displacedmedium moves in the same direction through said passage irrespective of the direction of rotation, the outer end of said shaft bein constructed for coupling to an external driving means;

13. A high speed rotary pump apparatus for displacing gaseous medium which comprises a casing having a peripheral wall and end walls forming a working chamber and having an axial extension provided with a hollow interior open-.

ing through one of said end walls into said chamber, a rotor having a barrel portion eccentrically arranged in said chamber, said barrel having one end in working relation to one end wall of the casing and the other end in working relation to the other end wall of the casing and a shaft projecting from at least one end wall of the barrel, said rotor dividing said working chamber from the interior of said extension, said shaft extending from said barrel into said hollow extension and being supported in said extension, a plurality of vanes slidable through the wall of the barrel and rotatable therewith and adapted to produce chambers of varying volume within said working chamber, said casing having two chambers ofiset from and communicating with the working chamber, a passage in said extension interior around said shaft, said passage having a port atits end remote from said offset chamber, each of said offset chambers having an inlet and a delivery port, one of said ports for each chamber placing itssaid oilset chamber in communication with said passage, a conduit placing the other of said ports for each chamber in communication with said port in said passage and with the correspondin port in the other ofiset chamber, an intermediate opening'from said conduit and valve means in said conduit operative selectively to couple said intermediate opening directly with the last named port of one oilset chamber and to close it from the last named port of the other ofiset chamber and to by-pass said passage or to close said opening from both said communicating ports of the offset chambers and to couple said opening for communication with. said passage, separate closure means for closing the inlet port of one of said oifset chambers and means for closmg the delivery port of the other of said ofiset chambers for a chosen direction of rotation of said barrel and varies so that depending upon the chosen direction of rotation of said barrel and vanes only one of said inlet ports and only one of said delivery ports remain open and the displaced medium moves in the same direction through-said passage irrespective of the direction of rotation, the outer end of said shaft being constructed for coupling to an external driving means.

FRANK CHRISTIAN FULCHER. 

